Stuart Firth
This weekend started with preparing the MJT hornblocks. When I last bought some (at Uckfield) they had run out of 1/8″ hornblock bearings and weren’t sure if they were going to order more, so I bought some 2mm ones, and bored them out to 3mm in the lathe, then reamed them to 1/8″. This seems to have worked OK. A pillar drill would work too of course.
The units are assembled with 188 solder, not much, to avoid clogging up the running surfaces. Then each bearing has its bottom marked with an X before being fettled with fine files, emery sticks, and finally Brasso, until it runs smoothly up and down. They are then scrubbed clean and lubricated with powdered graphite. An hour and a half I’ll never get back, and it makes my hands hurt, but the result is worth it!
The units are assembled in the chassis using a spring to hold them in place around a jig axle supplied by London Road Models. Using the fixed rear axle as a datum and with the coupling rods firmly pressed onto the pointed ends to set the wheelbase correctly, the units were gently teased back and forth, up and down, until they were in the right place, with no tension between rods and axles or axles and bearings. It takes a while but when it feels right, a tiny blob of 145 solder secures each one in place followed by a final check, then 2 more tiny blobs each. This is not the place for neat seam-soldering, which could easily unsolder the components of the hornblock bearing unit. Once the centre axle is in place, it becomes the datum for the front axle and the process is repeated.
